Parenteral administration routes

Other routes of administration arc theoretically possible such as rectal route (rectal capsules and rectal suppositories) for drugs having systemic effects such a.s sedatives, tranquilizers, and analgesics topical route (patchs) for drug absorption (hormones or nicotine) into the systemic circulation parenteral route (administration of parenteral suspensions or implantation of compressed pellets). 

Parenteral drug administration means the giving of a drug by the subcutaneous (SC), intramuscular (IM), intravenous (IV), or intradermal route (Fig. 2-5). Other routes of parenteral administration that may be used by the primary care provider are intralesional (into a lesion), intra-arterial (into an artery), intracardiac (into the heart), and intra-articular (into a joint), hi some instances, intra-arterial dragp are administered by a nurse. However, administration is not by direct arterial injection but by means of a catheter that has been placed in an artery. 

More than half of the patients receiving this drug by the parenteral route experience some adverse reaction. Severe and sometimes life-threatening reactions include leukopenia (low white blood cell count), hypoglycemia (low blood sugar), thrombocytopenia (low platelet count), and hypotension (low blood pressure). Moderate or less severe reactions include changes in some laboratory tests, such as the serum creatinine and liver function tests. Other adverse reactions include anxiety, headache, hypotension, chills, nausea, and anorexia Aerosol administration may result in fatigue a metallic taste in the mouth, shortness of breath, and anorexia... 

MANAGING ANXIETY. Fhtients may exhibit varying degrees of anxiety related to tiieir illness and infection and die necessary drug therapy. When these drug are given by die parenteral route, patients may experience anxiety because of the discomfort or pain that accompanies an IM injection or IV administration. The nurse reassures die patient that every effort will be made to reduce pain and discomfort altiiough complete pain relief may not always be possible. 

Promoting an Optimai Response to Therapy Heparin preparations, unlike warfarin, must be given by the parenteral route, preferably SC or IV The onset of anticoagiilation is almost immediate after a single dose. Maximum effects occur witiiin 10 minutes of administration. Clotting time will return to normal witiiin 4 hours unless subsequent doses are given. 

Iron salts occasionally cause gastrointestinal irritation, nausea, vomiting, constipation, diarrhea, headache, backache, and allergic reactions. The stools usually appear darker (black). Iron dextran is given by the parenteral route Hypersensitivity reactions, including fatal anaphylactic reactions, have been reported with the use of this form of iron. Additional adverse reactions include soreness, inflammation, and sterile abscesses at the intramuscular (IM) injection site Intravenous (IV) administration may result in phlebitis at the injection site When iron is administered via the IM route, a brownish discoloration of tlie skin may occur. Fhtients with rheumatoid arthritis may experience an acute exacerbation of joint pain, and swelling may occur when iron dextran is administered. 

On occasion, a patient may need to self-administer vasopressin by the parenteral route. If so, the nurse instructs the patient or a family member in the preparation and administration of the drug and measurement of the specific gravity of the urine. 

One adverse reaction common to all solutions administered by the parenteral route is fluid overload, that is, the administration of more fluid than the body is able to... 

Delivery of peptides and proteins via the gastrointestinal tract has not been successful because of poor penetration through the intestinal epithelium and high levels of proteolytic activity in the gastrointestinal tract. Liposomal encapsulation of proteins and peptides will not improve the efficiency and capacity of this absorption pathway considerably (e.g., Ryman et al., 1982 Machy and Leserman, 1987 Weiner and Chia-Ming Chiang, 1988). These difficulties in delivery via the oral route caused the parenteral route to remain the preferred route for the administration of therapeutic peptides... 

Besides the inhalative use, the development of a drug formulation for A9-THC has to address other bioavailabihty questions. A major problem is the hpophiUcity and poor solubiUty in water, hmiting oral uptake when given orally. Because of this, other parenteral routes of apphcation are imder investigation like puhnonal uptake by vaporization, subUngual or intranasal administration, and apphcation by injection of A9-THC incorporated in hpo-somes. 

Maintaining adequate nutritional status, especially during periods of illness and metabolic stress, is an important part of patient care. Malnutrition in hospitalized patients is associated with significant complications, including increased infection risk, poor wound healing, prolonged hospital stay, and increased mortality, especially in surgical and critically ill patients.1 Specialized nutrition support refers to the administration of nutrients via the oral, enteral, or parenteral route for therapeutic purposes.1 Parenteral nutrition (PN), also... 

Parenteral administration of drugs by intravenous (IV), intramuscular (IM), or subcutaneous (SC) routes is now an established and essential part of medical practice. Advantages for parenterally administered drugs include the following rapid onset, predictable effect, predictable and nearly complete bioavailability, and avoidance of the gastrointestinal (GI) tract and, hence, the problems of variable absorption, drug inactivation, and GI distress. In addition, the parenteral route provides reliable drug administration in very ill or comatose patients. 

In recent years, parenteral dosage forms, especially IV forms, have enjoyed increased use. The reasons for this growth are many and varied, but they can be summed up as (a) new and better parenteral administration techniques, (b) an increasing number of drugs that can be administered only by a parenteral route, (c) the need for simultaneous administration of multiple drugs in hospitalized patients receiving IV therapy, (d) new forms of nutritional therapy, such as intravenous lipids, amino acids, and trace metals, and (e) the extension of parenteral therapy into the home. 

Some parenteral routes of administration were less effective than others in producing an increase in the frequency of benign or malignant tumors, including intravenous, submaxillary, and intrahepatic... 

Ethinyl estradiol is a semisynthetic estrogen that has similar activity following administration by the oral and parenteral routes. 

No antibody activity was found after oral immunization in any of the individual rabbits immunized with liposphere R32NS 1-vaccine formulation. However, rabbit immunization by all parenteral routes tested resulted in enhanced immunogenicity, with increased antibody IgG levels over the entire postimmunization period. The individual rabbit immune response shows that immunization by subcutaneous injection was the most effective vaccination route among all parenteral routes of administration tested. 

The dosing regimens can be quite variable and at times very techniqueintensive. These chemicals are almost always administered by a parenteral route of administration normally intravenously or subcutaneously. Dosing regimens have run the range from once every two weeks for an antihormone vaccine to continuous infusion for a short-lived protein. 

The parenteral routes include three major ones IV (intravenous), IM (intramuscular), and SC (subcutaneous) and a number of minor routes (such as intraarterial) that are not considered here. Administration by the parenteral routes raises a number of special safety concerns in addition to the usual systemic safety questions. These include irritation (vascular, muscular, or subcutaneous), pyrogenicity, blood compatibility, and sterility (Avis, 1985 Ballard, 1968). The background of each of these, along with the underlying mechanisms and factors that influence the level of occurrence of such an effect, are discussed in Chapter 11. 

The characteristics of the fluid to be injected will also influence the choice of parenteral routes. The drug must be compatible with other fluids (e.g., saline, dextrose, Ringer s lactate) with which it may be combined for administration to the patient, as well as with the components of the blood itself. 

There are certain clinical situations in which a parenteral route of administration is preferred to other possible routes. These include the following. 

When the first-pass effect of a drug going through the liver must be avoided, a parenteral route of administration is usually chosen, although a sublingual route or dermal patch will also avoid the first-pass effect. 

The present chapter deals with calculations involving isotonicity, pH, and buffering of topical preparations. The discussion presented here is also relevant to the dosage forms for other routes of administration including parenteral routes. 

A nutritional deficit often exists in hospitalized patients. There are many conditions and diseases for which nutritional support is recommended by enteral or parenteral routes of administration. Provision of nutrients by vein, in amounts sufficient to maintain or achieve anabolism, is referred to as total parenteral nutrition (TPN). 

The average adult body contains approximately 4 g of iron, of which roughly two-thirds exists in the form of hemoglobin. Treatment of certain types of anemias usually consists of dietary supplementation or the administration of therapeutic iron preparations by oral and parenteral routes. Iron is often administered by i.m. as iron-dextran complex which is ferric hydroxide and dextran containing 50 mg of iron per milliliter. 

Many studies have been carried out regarding the absorption of peptides and proteins after pulmonary drug dehvery. The perspectives of a non-parenteral route of administration for larger proteins led to studies on the pulmonary absorption of proteins of different size. To date, over 30 different proteins have been evaluated with regard to absorption rate and... 

The IM and SC routes are by far the most frequently used extravascular parenteral routes of drug administration in farm animals. The less frequently used parenteral routes have limited application, in that they aim at directly placing high concentrations of antimicrobial agent close to the site of infection. These routes of administration include intra-articular or subconjuctival injection and intra-mammary or intra-uterine infusion. These local routes differ from the major parenteral routes in that absorption into the systemic circulation is not a prerequisite for delivery of drug to the site of action. The combined use of systemic and local delivery of drug to the site of infection represents the optimum approach to... 

Ideally, toxicology studies should mimic, as near as possible, human exposure. Thus, both the route of administration and the exposure should, where possible, be similar to that in man. The classic route of administration in man is oral and thus most toxicology studies are conducted by the oral route. Elowever, parenteral routes may be used either to mimic the clinical route or to ensure exposure. The administration of some medicines is directly on to highly differentiated surfaces such as the alveolar surface of the lungs or the skin. It is, therefore, important to assess the topical irritancy, absorption and subsequent systemic toxicity following such applications. It should be remembered that some compounds, for example, chlorinated hydrocarbons, may be more toxic when given by the inhalation route than when given orally or may directly affect... 

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